Are you looking for just a spare set, or are your hubs bad and you need a complete set to replace them?
From what I have read about the KKE wheels, a few people have had fitment problems, and some have had premature bearing failure, but the majority of people have not had a significant problem, but none of them were extremely hard on the wheels like a pro rider would be. If you got a set, I would consider changing the bearings out for some Japanese or US made ones.